The present disclosure is related in general to wellsite equipment such as oilfield surface equipment, downhole assemblies, and the like.
The statements made herein merely provide information related to the present disclosure and may not constitute prior art, and may describe some embodiments illustrating the invention. All references discussed herein, including patent and non-patent literatures, are incorporated by reference into the current application.
Coiled tubing is used in such oilwell operations as fluid pumping, fracturing, acidizing, and drilling. The fluids pumped through the coiled tubing may also used to activate downhole tools, and pressure variations in the fluid can be monitored to obtain basic information on downhole conditions. Data can be transmitted inside the coiled tube using fiber optic cables, typically consisting of small-diameter metallic tubes that contain a number of optical fibers. These cables can be inserted into the coiled tubing at the well surface by pumping them through coiled tubing at the take-up spool. When the fiber optic cable reaches the tool-end of the coiled tubing it is attached to the tool as needed.
There are issues concerning typical fiber optic cables disposed in metallic tubes used in coiled tubing, such as an increased size of the metallic tube creating stiffness and/or pumpability issues, the size of the metallic tubes limits the amount of area available for electrical power transmission, and the metallic tube's overall strength-to-weight ratio, which may limit the depth capability of the metallic tube.
It remains desirable to provide improvements in oilfield equipment and/or downhole assemblies.